In many current applications, track links that are part of track chains develop a scallop pattern on their top or rail surfaces that contact various drive and support members of the undercarriage including rollers and idler wheels. The scallops look like depressions on the rail surface of the links. These depressions are caused by contact of the rollers and the idler in a consistent place on the link as the track chain continuously revolves around on the drive sprocket, idler wheels and the rollers. In many cases, the track links have rails with a center portion that is thicker in a direction parallel to the axis of rotation of the idler wheel as compared to a similar thickness of the end portions. Consequently, an idler wheel and roller tend to contact the center portion more completely and less completely at the ends where that portion of the link is not overlapped by an adjacent link. This leads a deeper more complete scallop, often referred to as a primary scallop, being formed at the center of the rail portion of the track link, while a secondary scallop that this less complete may be formed at the end portions of the rail of the track link. These secondary scallops are often positioned at the ¼ position of the rail, measured from the front of the rail, and at the ¾ position of the rail, also measured from the front of the rail, while the primary scallop would be located between the ¼ and ¾ positions.
Scalloped track links may lead to various problems. For example, over time, the manner in which the idler wheel and rollers contact the links may become uneven, causing vibration that may lead to an uncomfortable ride. Also, this may lead to maintenance issues for the undercarriage and the machine.